Terminal block



July 16, 1968 A. L. MANICHL 3,393,397

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ATTORNEYS A. L. MANICHL TERMINAL BLOCK July 16, 1968 5 Sheets-Sheet 2 Filed Aug. 31, 1964 F/y. Q

W ATTORNEY$ July 16, 1968 A. MANICHL TERMINAL BLOCK 3 Sheets-Sheet 3 Filed Aug. 31, 1964 I INVENTOR Her/we L. M /wc'//1 m ATTORNEYS United States Patent 3,393,397 TERMINAL BLOCK Arthur L. Manichl, 1219 11th St., Lorain, Ohio 44052 Filed Aug. 31, 1964, Ser. No. 393,320 14 Claims. (Cl. 339-95) This invention relates to connections between electric wires and in particular to improvements in terminal blocks, junction boxes and the like employing screwless wire connections.

It is known in the prior art to replace the terminal screws of household wall receptacles with a screwless, pressure-locking terminal in which the conducting wires are connected to the device by merely inserting the bar-ed ends through an opening in the housing or body of the device. These pressure-locking terminals conventionally include a flexible metal locking tongue whose free end frictionally engages the end of the wire as the latter is inserted through the opening and holds it against a conducting surface within the receptacle. The tongue also bites into the wire and strongly resists its withdrawal until a screwdriver or other pointed tool is inserted through another opening to displace the tongue from its locking position.

It is one object of the present invention to provide an improved terminal block of simple and economic construction which employs pressure-lock terminals and which is adapted to effect a large number of electrical connections in a small space. Terminal blocks constructed according to the principles of this invention may be readily substituted for existing screw type terminal blocks found in household and commercial junction boxes and the like and are advantageous from the standpoint of providing for a larger number of connections than the original equipment and from the standpoint of reducing the time required for making connections. In addition the terminal blocks of the present invention may be employed in such devices as ceiling boxes, wall outlets and fluorescent light fixtures for the purpose of making connections which are conventionally made by splicing.

It is a further object to provide a unitary molded plastic junction box incorporating, broadly, a plurality of moldedin pressure type terminals for connecting the lead-in wires to other wires. More specifically, it is an object to provide a molded box having a plurality of molded-in pressure type terminals of an improved, economical construction.

It is a still more specific object to provide a plastic terminal block having a plurality of molded-in pressure type terminals in which the terminals are constructed of a strip of metal bent at a right angle to form two arms, one of the arms having a tongue punched therefrom for gripping a wire between its free end and the other arm.

The invention will be further understood from the following detailed description taken with the drawings in which:

FIGURE 1 is a perspective view of a plastic terminal block having a plurality of pressure type terminal bars each of which is adapted to connect one incoming wire to one outgoing wire.

FIGURE 2 is a perspective view of one of the terminal bars of FIGURE 1;

FIGURE 3 is a sectional view, on an enlarged scale, taken on the line 33 of FIGURE 1 and illustrating the operation of a terminal bar;

FIGURE 4 is a sectional view taken on the line 4-4 of FIGURE 1;

FIGURE 5 is a perspective view of a modified form of the terminal bar of FIGURE 2;

FIGURE 6 is a perspective view of another form of plastic terminal block having pressure type terminal bars each of which is adapted to connect one incoming wire with one outgoing wire;

FIGURE 7 is a perspective view of one of the terminal bars of FIGURE 6;

FIGURE 8 is a perspective view of a modified form of the terminal bar of FIGURE 7;

FIGURE 9 is a perspective view of a terminal block having pressure terminal bars adapted to connect a pair of incoming wires to a plurality of outgoing wires;

FIGURE 10 is a perspective view of one of the terminal bars of the block of FIGURE 9;

FIGURE 11 is a transverse sectional view of the block of FIGURE 10 shown retained in a ceiling box or the like;

FIGURE 12 is a perspective view of a modified form of the terminal bar of FIGURE 10;

FIGURE 13 is a perspective view of a molded plastic junction box in which pressure type terminal bars have been incorporated during the molding operation; and

FIGURE 14 is a vertical sectional view of the junction box of FIGURE 13 illustrating its manner of use.

Referring to FIGURES 1-4 there is shown a small terminal block 10 adapted to connect five incoming wires to five outgoing wires by means of pressure terminal bars 12 embedded in the block 10. Connection of one wire with another is effected by simply inserting the bare ends of each wire into an appropriate hole 14, as will be more fully described hereinafter. The particular block which is illustrated may be, for example, 3% inches long, 1 /2 inches wide and /2 inch thick and may be employed with or without a housing wherever connections between one set of wires and another set are to be made. Connections of this kind are conventionally made by splicing with the aid of wire nuts or by means of a terminal block provided with conventional screw-type terminals. These conventional operations effect satisfactory connections, but they are time consuming and require a housing of substantial size for enclosing the connections. When a large number of connections is to be made, the use of either wire nuts or screw terminals becomes cumbersome and confusing due to the crowding of the wires in the housing. On the other hand, the use of the pressure type terminal block of the present invention permits the connections to be made or released with a minimum of time and with little or no excess lengths of wire as is required for splicing or for attaching to screw terminals.

The block 10 of FIGURES 1-4 is constructed of electrically non-conductive plastic material which is molded about the five terminal bars 12 to insulate them from each other. A pair of screws 13 extends downwardly between the outer pairs of terminal bars 12 for securing the block 10 to a base (not shown). As best shown in FIGURE 2 each terminal bar 12 is formed of a short thin strip of metal, the ends of which have been bent at right angles to form a channel configuration having a pair of relatively short depending flanges 16 joined by a web 18. The web 18 is somewhat elongated with its axis extending at a right angle to the flanges 16. A tongue 20 is cut in the web 18 adjacent its junction with each flange 16. The tongues 20 have free ends 22 terminating substantially at the planes of the flanges 16 and are sufliciently flexible to be pivoted downwardly by the force of an electric wire pressed against the top surface thereof.

As best seen in FIGURES 3 and 4, each of the terminal bars 12 extends transversely of the block 10 within a box-like hollow space 24, the outer surfaces of the flanges 16 and the upper surface of the web 18 being in contact with the plastic so as to hold the terminal bars 12 in place. Each vertical, wire-receiving hole 14 extends through the top of the block 10 to the free end 22 of each tongue 20, and a release slot 26 is provided near the base of each tongue 20.

The operation of the tongue 20 in making an electrical connection is clearly illustrated in FIGURE 3 where, on the left side, there is shown a bare-ended electric Wire 28 frictionally held between the free end 22 of one of the tongues 20 and the adjacent flange 16. This locked-in position is effected by manually inserting the end of the wire 28 into the hole 14 and pushing it downwardly so as to deflect and slide past the free end 22 of the tongue. A very slight upward pull on the wire 28 after it has been fully inserted causes the free end 22 of the tongue to bite into the surface of the wire and simultaneously forces the wire 28 firmly against the adjacent flange 16. As a further aid in aligning and holding the wire 28, a small socket 30 is formed in the plastic below the tongue 20 for receiving the end of the wire 28. For clarity, clearance between the wire 28, flange 16 and tongue 20 have been shown, but it will be apparent that the wire 28 is, in fact, frictionally engaged by the terminal parts.

When it is desired to disconnect a wire 23 from the block 10, a screwdriver 32 or other pointed tool is inserted in the appropriate release slot 26 and pushed downwardly against the tongue 20. This action, as seen on the right in FIGURE 3, pivots the free end 22 of the tongue downwardly and away from the wire 28 thus releasing the latter so that it may be withdrawn from the hole 14. It will thus be seen that the block 10 of FIGURES l4 may be employed to connect from one to five incoming wires to a corresponding number of outgoing wires, each connection being effected by locking the ends of an incoming and outgoing wire to the opposite ends of one of the terminals 12.

A second form of terminal bar 12a which may be employed in the block of FIGURE 1 is shown in FIG- URE 5. In this construction there is also provided a web 18a, a pair of right angle, depending flanges 16a and a tongue 20a associated with each flange 16a. Here, however, each of the flanges 16a has an outwardly bulging center portion 34 which provides an inner convex surface against which a wire will be held by the free end 22a of the tongue 20a. Also, the free end of the tongue is cut away so that a relatively wide space, suitable for receiving heavy gauge wire, exists between the convex surface of the flange 16a and the end 22a of the tongue. In operation, the terminal bar 12a of FIGURE 5 is the same as that of the terminal 12 of FIGURES l-4, except that wire of less than a predetermined diameter cannot be locked in place.

In FIGURE 6 there is shown a terminal block 10b which is similar to that of FIGURES 1-4, but which differs in that the incoming and outgoing wires may be attached at opposite sides of the block rather than both sets of wires being attached along the same surface. In this construction, as best seen in FIGURE 7, there are provided terminal bars 12b which, as before, are formed of a strip of metal bent to provide a web 18b and a pair of parallel flanges 16b. These terminal bars 12b differ somewhat from those previously described in that rectangular locking tongues 20b are cut from the flanges 16b rather than from the web 18b and have free ends 22b lying substantially in the plane of the web 18b. The principle of operation is the same as previously described, except that an electric wire will be clamped between the web 18]) and the end 22b of a tongue rather than between a flange and a tongue end. The terminal bars 12b are disposed within the block 10b in longitudinally spaced positions such that the flanges 16b are parallel to the vertical sides of the block. The wire-receiving holes 14b and the release slots 26b are, accordingly, horizontal in this embodiment.

FIGURE 8 shows a slightly different terminal bar 12c which may be employed in the block 10b of FIGURE 6. The terminal bar 120 is analogous to that of FIGURE 5 in that the surface against which a wire is clamped is concave. As shown, a longitudinal center portion of the web 180 has been deformed outwardly at 34c to form a groove in which both wires of the connection will be held by the free ends 220 of the tongues 200.

FIGURE 9 illustrates another terminal block 10d which is adapted to connect each of two incoming wires to four outgoing wires. In thisconstruction there are provided two spaced terminal bars 12d extending longitudinally within the block, each of which has five locking tongues 200.. As shown in FIGURE 10 each terminal bar is an elongated channel-shaped member having a web 18d and a pair of parallel right angle flanges 16d lying in planes which are parallel to the axis of the web 18d. The locking tongues 20:! are cut in the web 1&1 at intervals along its length with their free ends 22d adjacent one of the flanges 16:! so as to provide for the connection of five wires to each terminal bar 12d. I

In FIGURE 11 the terminal block 10d is shown in transverse cross section carried as an insert in a metal ceiling box 36 or the like. The box 36 is representative of any of a variety of housings which are embedded in or attached to building ceilings or walls for the purpose of inclosing connections between electric wires. As shown, the box 36 has a bottom wall 38, upstanding side walls 40 and upstanding end walls, one of which is shown at 42. As is conventional in box construction the walls are provided with circular knock-outs 44 which may be punched out as desired.

The terminal block 10d is secured in the box 36 in any suitable manner depending on the details of the box construction. As shown, one or more screws 46 are inserted through holes in the bottom wall 38 and screwed into tapped holes 48 in the lower surface of the block 10d. However, clips or brackets or other mounting means may be employed. Electrical connections are made by removing the desired number of knock-outs 44, passing the ends of the wires into the box through the resulting holes and inserting the bare ends into the appropriate hole 14d in the top of the block 10d. For example, a two-wire, current-bearing cable may be inserted through the knock-out hole in the end wall 42 and one of the wires connected to each of the two terminal bars 12d by insertion into the nearest hole 14d. Two wire cables, up to a total of four, for conducting current to various ceiling fixtures, wall receptacles and the like may then be brought in through the knock-out holes in the side walls and connected across the two terminal bars 12d by insertion into the remaining holes 14d.

In FIGURE 12 there is illustrated a terminal bar 12e which may be substituted for the terminal bars shown in FIGURE 9. The modified construction differs from the bars 12d in that the flange which does not cooperate with the tongue to lock a wire in place is omitted. In addition, the tongues 20s are cut slightly shorter so that there is a narrow space between their ends 22c and the remaining flanges 162. It will be appreciated at this point that all of the terminal bars which have been described are very easily fabricated inasmuch as .only simple bending and cutting operations are required. A further economic advantage is that different types of terminal bars may be fabricated from a single more complex bar by dividing the original after the tongues have been cut. For example, if a strip of metal is first bent into the form of a channel having flanges lying in planes which are parallel to the longitudinal axis of the web, a row of tongues may be punched along the web adjacent each flange. The resulting terminal bar may be employed in that form, or it maybe cut to form smaller bars of thekinds shown in FIGURES 2 and 12. That is, if the channel-shaped bar is cut along planes which are at right angles to the flanges, a plurality of bars each like that of FIGURE 2 results. If the channel-shaped bar is out along a central plane which is parallel to the flanges, two bars each like that .of FIGURE 12 result.

Referring to FIGURES l3 and I4 there is shown an insulating plastic junction box 50 in which terminal bars 12 are incorporated in the plastic material of the box rather than in a separate terminal block insert. As shown, the box 50 includes parallel side walls 52, parallel end walls 54 and a relatively thick, integral bottom wall 56 in which the terminal bars 12 are embedded. Preferably the complete box is molded as a unit with the bars 12c incorporated in the plastic during the molding operation. However, the bars 12 may be inserted longitudinally into appropriately molded recesses in the bottom wall 55 after the molding operation. In either case, the box 50 is very economical to fabricate because it requires less material and fewer assembly steps than conventional junction boxes which employ a separate screw-type terminal block. In conventional practice the terminal block is made by a series of fabricating and assembly steps and must then be incorporated into a junction box with screws, brackets or other fastening means. Since the pressure type connections require less wire and may be easily effected, the box 50 can be smaller than existing boxes thereby providing further economies.

The box 50 illustrated in FIGURES l3 and 14 is intended for use with conventional Romex cable or other three-wire cable and to this end there are provided three terminal bars 12 disposed within separate cavities 58 in the bottom wall 56 in parallel relationship. Each of the bars 12 is identical with that of FIGURE with the exception .of the number of tongues, the bars 12 having only four tongues The inner surface of the bottom wall 56 is provided with wire-receiving holes 14 and release slots 26 extending to the tongues 20f in the same manner as the equivalent holes and slots in the previously described terminal blocks.

In use, a three-wire cable 59 is first brought into the box 50 through a hole 60 provided in one of the side or end walls for that purpose. Each of the wires 62, 64, 66, one of which is a ground wire, is connected to a different terminal block 12 by inserting its ends into one of the holes 14 and pushing it downwardly until the end lies in one of the recesses provided for that purpose. In this position, the tongues 20' prevent removal of the wires. As many as three other cables, one of which is shown at 68 may then be brought into the box through other holes and their wires connected to the corresponding wires of the first cable by inserting the ends in the appropriate holes 14 It will be appreciated that the junction box 50 is illustrative of a variety of electrical devices employed for making connections and that the principle of providing molded-in terminal bars may be applied to other devices such as outlet receptacles, trafiic controller terminal blocks, ceiling and wall boxes and fuse boxes. The terminal bars may be embedded in a side or end wall in some arrangements or in an integral projection on any of the walls. For example, a projection on a bottom wall might take the form of the block of FIGURE 6 in which case wires would be inserted into the sides of the projection.

It will be appreciated also that the separate terminal blocks of the present invention may be employed in a variety of ways either as inserts for existing junction boxes or other electrical enclosures where they supplant con-- ventional screw-type terminal blocks, or as additional equipment to take the place of spliced connections. Accordingly, the details of the described terminal bars, terminal blocks and junction boxes are not intended to be limiting except as they appear in the appended claims.

What is claimed is:

1. A molded plastic junction box or the like for effecting and enclosing electrical connections between wires, said box comprising: integrally molded side, end and bottom walls of electrically insulating plastic material; at least two conductive terminal elements within said box for effecting electrical connections between ends of wires said terminal elements being embedded in spaced-apart relationship within one of said walls, each of said elements being constructed in the form of an electrically conductive strip having two leg portions defined by a straight line bend of approximately in the material of the strip, each of said terminal elements having at least two pressure type couplings, said couplings being defined by locking tongues struck out of the material of one of said leg portions, said locking tongues being disposed in side by side relationship, said tongues having their base along a line generally parallel to the straight line bend of the respective terminal element and having their free ends facing toward the other leg portion of the respective terminal element and spaced equidistant from said other leg portion and sufficiently close thereto such that each of said free ends is operable to clamp a wire end against said other leg portion, said one wall having a wire-inserting hole extending from the interior of said box to the free end of each of said tongues whereby insertion of the end of a wire into said hole effects locking of the end in the respective coupling, said one wall further having a wire release hole extending from the interior of said box to near the base of each of said tongues whereby insertion of a pointed tool in said release holes moves said tongues away from a locking position.

2. A device as in claim 1 wherein each of said terminal elements is channel-shaped having a web member and a pair of flange members, said tongues being formed in one of said members and having free ends facing and positioned close to the other member.

3. A device as in claim 1 wherein the surface of said other leg portion which said tongues face is concave adjacent each tongue end.

4. A device as in claim 1 wherein each of said terminal elements is an elongated strip of generally L- shaped cross section, said tongues being formed in one of the legs of the L and having free ends facing and positioned close to the other leg.

5. A terminal block for effecting electrical connections between wires comprising: a relatively thin plate of elec trically insulating plastic material having embedded therein a plurality of spaced apart conductive terminals for effecting electrical connections between ends of wires; each of said terminal elements being formed of a single strip of resilient conductive material bent and cut to form a pair of leg portions extending at substantially a right angle to each other, each of said terminal elements having at least two pressure type couplings, said couplings being defined by locking tongues struck out of the material of one of said leg portions, said locking tongues being disposed in side by side relationship, said tongues having their bases along a line generally parallel to the junction line between the leg portions of the respective terminal element and having their free ends facing toward the other leg portion of the respective terminal element and spaced equidistant from said other leg portion and sufficiently close thereto such that each of said free ends is operable to clamp a wire end against said other leg portion, said plate having a wire-inserting hole extending from a surface thereof to the free end of each of said tongues whereby insertion of the end of a wire into said hole effects locking of the end in the respective coupling, said plate further having a wire-releasing hole extending from a surface thereof to near the base of each of said tongues whereby insertion of a pointed tool in said releasing holes moves said tongues away from a locking position.

6. A terminal block or the like in combination with walls defining an open top box, for effecting electrical connections between wires comprising a relatively flat thin plate of electrically insulating plastic material; a plurality of spaced apart conductive terminal strips disposed side by side within and surrounded on all exterior surfaces by the material of said plate, each of said terminal strips being constructed as a single strip of metal shaped to provide a plurality of pressure type couplings of the kind which have a movable element for frictionally gripping a Wire end when the latter is inserted into the coupling and for releasing the wire when deflected out of a gripping position by a tool, said plate having a plurality of wire inserting apertures each of which extends from a surface of said plate to one of said pressure type couplings, said plate also having a plurality of release apertures each of which extends from a surface of said plate to one of said pressure type couplings for providing access to the respective coupling by a release tool, said plate and apertures being arranged so that all of said apertures are accessible from the inside of the box, at least one of said walls having at least one hole therethrough for the passage of a multiwire cable.

7. The combination of claim 6 wherein said plate forms one wall of said box.

8. An electrical terminal comprising a single strip of electrically conductive material bent to form two arm portions extending at substantially a right angle to each other and at least one resilient tongue struck out of the material of one of said arm portions thereby providing an opening in said one arm for the insertion of an electrically conductive wire, said tongue having a base which is integral with said one arm at a location remote from said bend an having a free end disposed adjacent said bend, said tongue at least partly closing said opening and being resiliently deflectable by an electrical wire inserted into said opening, said free end of said tongue terminating in a gripping edge which is disposed sufiiciently close to the other of said arm portions that an electrical wire inserted into said opening in a direction parallel to said other arm automatically becomes clamped between said gripping edge and said other arm due to the resilience of said tongue, said gripping edge strongly resisting withdrawal of the wire.

9. An electrical terminal as in claim 8 wherein there are a plurality of said tongues and openings in said one arm portion, said tongues being arranged in side-by-side, spaced-apart relationship.

10. An electrical terminal as in claim '8 wherein the length of said tongue is less than the length of the opening whereby heavy gauge wire may be received within said opening.

11. An electrical terminal as in claim 8 wherein there are at leasttwo resilient tongues and further including a block of insulating material surrounding the external surfaces of said electrically conducting strip, said block having at least four holes therein, two of said holes extending in a straight line from the free ends of said tongues to the surface of said block to receive electrically conducting wires and two of said holes extending in a straight line from the bodies of said tongues to the surface of said block to receive a tool for deflecting the frceends of said tongues away from clamped wires. 6

12. An electrical terminal as in claim 8 wherein said terminal is channel shaped so as to define a web portion and a pair of fiangeportions, said bend defining. the junction line between said web portion and one of said flange portions and another bend defining the junction line between said web and the other flange portion, and wherein there is at least one tongue associated with each bend, the free end of each tongue facing its respective bend.

13. An electrical terminal as in claim 12 wherein both said tongues are formed in said web portion, the free ends of said tongues facing in opposite directions.

14. An electrical terminal as in claim 12 wherein one of said tongues is formed in one of said flange portions and wherein the other of said tongues is formed in the other flange portion, the free ends of said tongues facing in the same direction.

References Cited UNITED sTATEs PATENTS 2,685,720 8/1954 Petri 24-73 2,795,677 6/1957 Slater. 3,019,406 1/1962 Slater. 3,205,407 9/1965 Thompson 317 101 FOREIGN PATENTS 76,151 7/1953 Denmark.

MARVIN A. CHAMPION, Primary Examiner.

EDWARD C. ALLEN, Examiner.

I. H. MCGLYNN, Assistant Examiner. 

1. A MOLDED PLASTIC JUNCTION BOX OR THE LIKE FOR EFFECTING AND ENCLOSING ELECTRICAL CONNECTIONS BETWEEN WIRES, SAID BOX COMPRISING: INTERGRALLY MOLDED SIDE, END AND BOTTOM WALLS OF ELECTRICALLY INSULATING PLASTIC MATERIAL; AT LEAST TWO CONDUCTIVE TERMINAL ELEMENTS WITHIN SAID BOX FOR EFFECTING ELECTRICAL CONNECTIONS BETWEEN ENDS OF WIRES SAID TERMINAL ELEMENTS BEING EMBEDDED IN SPACED-APART RELATIONSHIP WITHIN ONE OF SAID WALLS, EACH OF SAID ELEMENTS BEING CONSTRUCTED IN THE FORM OF AN ELECTRICALLY CONDUCTIVE STRIP HAVING TWO LEG PORTIONS DEFINED BY A STRAIGHT LINE BEND OF APPROXIMATELY 90* IN THE MATERIAL OF THE STRIP, EACH OF SAID TERMINAL ELEMENTS HAVING AT LEAST TWO PRESSURE TYPE COUPLINGS, SAID COUPLINGS BEING DEFINED BY LOCKING TONGUES STRUCK OUT OF THE MATERIAL OF ONE OF SAID LEG PORTIONS, SAID LOCKING TONGUES BEING DISPOSED IN SIDE BY SIDE RELATIONSHIP, SAID TONGUES HAVING THEIR BASE ALONG A LINE GENERALLY PARALLEL TO THE STRAIGHT LINE BEND OF THE RESPECTIVE TERMINAL ELEMENT AND HAVING THEIR FREE ENDS FACING TOWARD THE OTHER LEG PORTION OF THE RESPECTIVE TERMINAL ELEMENT AND SPACED EQUIDISTANT FROM SAID OTHER LEG PORTION AND SUFFICIENTLY CLOSE THERETO SUCH THAT EACH OF SAID FREE ENDS IS OPERABLE TO CLAMP A WIRE END AGAINST SAID OTHER LEG PORTION, SAID ONE WALL HAVING A WIRE-INSERTING HOLE EXTENDING FROM THE INTERIOR OF SAID BOX TO THE FREE END OF EACH OF SAID TONGUES WHEREBY INSERTION OF THE END OF A WIRE INTO SAID HOLE EFFECTS LOCKING OF THE END IN THE RESPECTIVE COUPLING, SAID ONE WALL FURTHER HAVING A WIRE RELEASE HOLE EXTENDING FROM THE INTERIOR OF SAID BOX TO NEAR THE BASE OF EACH OF SAID TONGUES WHEREBY INSERTION OF A POINTED TOOL IN SAID RELEASE HOLES MOVES SAID TONGUES AWAY FROM A LOCKING POSITION. 